Former Labour minister Clare Short today attacked the government's child poverty strategy after new figures revealed half of all children are living in or on the brink of poverty in many areas of the UK.

Research by the Campaign to End Child Poverty (ECPC) found more than a quarter (174) of all the UK's constituencies have at least half of children in families relying or benefits or working tax credit.

Short's Birmingham Ladywood constituency topped the grim league table with 81%, or 28,420, of its children in such families.

"These are disturbing figures, but they reflect the weakness of New Labour's anti-poverty strategy," Short said.

"The inner cities throughout the UK have similar problems. Ladywood is the worst because since the reorganisation in 1997 it consists of four inner city wards.

"This is a sad reflection of the growing inequality in the UK."

The ECPC, an umbrella group which includes Barnardo's, Save the Children and the TUC, released the figures ahead of a rally in central London this Saturday to urge the government to keep its promise to eradicate child poverty by 2020.

The ECPC uses those figures but also includes figures for those just above the poverty line, on 70% of median national income.

Their research shows child poverty is even more concentrated within some of the UK's 646 constituencies.

An estimated 98% of children living in two zones in Glasgow Baillieston – Central Easterhouse and North Barlarnark and Easterhouse South – are either in poverty or in working families that rely on top-up tax credits.

The figures were worse than expected, said the campaign's chairman, Martin Narey.

"Pockets of our country are in turmoil," he said. "These figures show us that there are millions more children than originally thought being failed by the system."

The ECPC also revealed the number of working parents who are struggling to provide for their children.

In Bradford West 44% of children (14,630) are in families that rely on working tax credit, according to figures calculated by the Centre for Economic and Social Inclusion.

The area has more children being looked after in working families relying on tax credits than in non-working families relying on benefits.

The campaign's director, Hilary Fisher, said: "It is because of this reality that we are pushing the government harder than ever to do more to end child poverty in our country – one that is ironically the fifth richest country in the world.

"The government needs to focus on areas where deprivation is worst."

Fisher said the government should take heed of research by the Institute for Fiscal Studies for the Joseph Rowntree Foundation showing the need for £2.8bn investment in benefits and tax credits to lift 1 million children out of poverty.

Without that, she added, Labour has no hope of hitting its interim target for halving child poverty by 2010.